Automatic control apparatus for centralized lubricating systems



H. R. TEAR Filed Feb. 18, 1950 v l l i M W g AUTOMATIC CONTROL APPARATUSFOR CENTRALIZED LUBRICATING SYSTEMS April 21, 1953 Hf ....e..

Patented Apr. 21, 1953 AUTQMATIC CONTROL APPARATUS FOR CENTRALIZEDVLURICAIINGr SYSTEMS Harry R, Tear,'Evanston, Ill. ,assignor-to Stewart-Chicago, Ill., a` corpora- Warner- Corporation, tion-.of .Virginia.Application Eebruary 18, 1950,.,Serial No. 144,878

2i Claims.

"My-inventionrelates generally to centralized i1u brigraftingl systems;Iand'jmore `particularly to improved'means forv controlling-theapplication and reli'ef 'of pressure alternately to ltwo conduitsconnected'to-measuring or feeder valves for supplying lubricant to partsto be lubricated.

In one typeof centralized lubricating system, thel measuring or feedervalves by'which the lubricant is measured andsupplied to the parts tobeflubricated; are connected between two line conduits;` and 4it-isnecessary,- for the proper operationA ofj these valves, that thelubricant be supplied under-pressure to one of--these conduitswhile-beingrelieyed from the other conduit, and vice-versa.` Inthepast;the apparatus required to'con-trol such application-of lubricantpressure to the conduits; was-generally complicated, including--suchparts as solenoid operated valves, pressure` operated-switches,relays, andthe like.

It-is the y-ob'jectof vmyinvention to provide an improved automaticcontrol apparatus which in-- cludesonly 'hydraulically operated parts,except for ain-electrically operated time clock mechanismforintermittently'energizing the motor driving the lubricant.

A furtherlobject is to provide an improved controlsystem for pressureapplication -to -centralized lubricatingsystems, which is .positive andreliable `in operation; simple in construction, and-which may bev.economically manufactureds Other objects will appear from theVyfollowing description, reference. being: hadvv to theaccompartying-drawing vwhich illustrates, inV part diag-rammatically,the improved control apparatus asappliedfto a. centralized.lubricating-1 system.

Referring-- tol the drawing, lubricant forfsup.- ply-.tethewentrahzedlubreatinsfsvstem S-fwthdrawn from a. reservoir l0.` by an electricmotor dri-venrpunjlp I2. which is operatedat periodic intervals by asuitable timeclock- Ul, which is preferably. of the .type-in which .theintervals between .closures of. the motor. controlling switch,as-.w'ellasthe duration of such switch closure, may be adjusted to suit.the particular requirements of. the, ycentralized lubricating. systemwith whiehitis employed.. The pump IadiSchareeS into a conduit I6 towhich control valvesy 20 .and 22 and a pressure relief valve 24 aredirectly connected The control iva-ive 29 comprises a body 26havingvcylindricalbores 28VV and 29 formed therein, the: upper-end itli'egbedy thema-,closed by a plug-30 lhaving aV cylindrical vbore 32`therein and haringen inlet y.valve Seat-.3.4. The plus 3.a.. alsohassan- Guile-1.1.36.; which... is peenneetedA to. the inletoaloadedicheckvalve 38, the loading-springllllv orf-,which :is of suchsize that' the valve; will-open under'a relatively low pressure as',`.for example, 200 `p. sri.A

A piston valve-member has piston parts llt, and` 41 respectivelyoperating in ,the-cylindricalbores 3,2; 28s,and 29, it being noted thatthe'bores 2.9 Yand 32 are approximately of the same diameter; while theborey 28A is of substantially larger diameter.V The'valve-member-Malso-includes anl inlet valve -48 -cooperable with the inlet port seatll/'and avent valve part 150-cooperab1e withva vent port seat 52. A coilspring-Misof such strength` thatthe valve 48-1 will remain seated untilthe pressure-withinthe conduit -I6 exceeds a mediumYh-igh Value as, forexample, 1000 11s. i. y

The-controL-valvev 22 is similar to the-valve-'20 in construction, andthe same referencefcha'ractersas used in the description of valveZbl-have beenapplied-to the corresponding partsofthe control valve22except that the inlet valve is designated as 49 and the outlet valveis designated as 5I; the valve operating spring-55,- which-correspondsto the-spring 5ft-is', however, a heavier spring and -is-adapted to holdVthe-valve .closed against a higher pressure, such, for example, as 1200p. s'. i.

The port tit-ofthe vvalve 22 is connected to the inlet of a loaded checkvalve 39-fwhich is similar tothe valve 38, andthe spring llllofwhieh'is-.of such strength that the valve-will likewise open iat a'pressureof approximately 200up. s. i.

The discharge side of the loaded check valve VIt-is connected 'to thelower end'of -the bore. 29

of-va-lve- 29: andthedisch'arge side ofthe-.check valve. 39fis similarlyconnected to the lower end of -the-.bore--of vthe control vvalve :22; Inaddition,

the. discharge'. sides of the-loaded check valves land 39 :are:connected'to line -conduits A and B'whioh supply-the lubricanttomeasuring or feeder valves '691, each being illustrated as supplyinglubricantto two-bearings 62. Themeasuring or 4feeder valve 50 may be ofany suitable type inwhich 'the valvenmay Ibe connected' to twolubricant-supplyiconduits. and by-'which--measul-'ed charges: oflubricant are discharged to .bearings upon the alternate applicationfand-relief .of lubricant-pressureinthe two-conduits to which th'evalves are connected.- .As-illustrative of this-type of-measuring orfeeder-valve, reference.: may be had to the patents to J T. Leonard No.2,440,410, and'R'. WederbergNc, 2,3,92g0'1'7 Thelower. end Yofthe here.2810ieontrel valve 2 0; is. .connected ,b y, aiA conduit 16.6 with the.lower 3 end of the bore 29 of the control valve 22. The vent ports forthe lower ends of the bores 29 of the control valves 20 and 22 aresuitably connected to a vent conduit 68 which is connected to thelubricant reservoir I0. The pressure relief check valve 24 has its inletport 10 connected to the conduit I6, the inlet port being normallyclosed by a valve 12 at the end of the stem 14 of a piston 16 which isfreely reciprocable in'a cylindrical bore 18 formed in the body 80 ofthe relief valve. The piston rod 14 is suitably guided in a cap 82threaded on the body 80, and the valve 12 is held in closed position bya coil spring 84 compressed between the cap 82 and the piston 16.Lubricant iiowing past the valve 12 is vented to the lubricant reservoirthrough the ventconduit 68. The force applied by the spring 18 issufcient to hold the valve 12 closed until the pressure attained in theconduit I6 is of a relatively high value, such, for example, as 1400 p..s. i.

Assuming that the system has been charged with lubricant and that thetime switch mechanism I4 has operated to cause the electric motor drivenpump i2 to supply lubricant under pressure to the conduit I6, thepressure within this conduit will build up until the pressure issufficiently high to force the valve 48 from its seat 34, which in theexample given, would be a pressure of 1000 p. s, i. from its seat, thefull pressure is, of course, ap" plied -to the top of the piston 45 andthe piston member 44 is therefore moved rapidly downwardly, causing itsoutlet valve 50 to be pressed against its seat 52. Lubricant is thenfree to flow past the valve 48 through the outlet port 3B and throughthe loaded check valve 38 to the line conduit A, and the pressure willbuild up in the conduit A causing all of the measuring or feeder valves69 which are connected to this conduit to operate and supply measuredcharges of lubricant to vat leasty one of the bearings connected to eachof these valves 6D.

The piston member 44 will be retained in its lowermost position with thevent valve 50 closed throughout the operation of the feeder valve 60 byvirtue of the fact that a pressure of at least 200 p. s. i. ismaintained at the upper end of the bore 32 by virtue of the effect ofthe loaded check valve 38. The pressure in the upper end of the bore32will therefore at all times be greater than that in the lower end ofthe bore 2'9 by at least 200 p. s. i., the load imparted by the checkvalve 38.

After all of the feeder valves 60 have been operated, the pressurewithin the line conduit A will build up so that the pressure in theconduit I6 will also increase, and this will continue until the pressureattained is sufficient to open the inlet Valve 49 of the control valve22, namely at 1200 p. s. i. for the exemplary pressures given. When thevalve 49 opens, the valve 5I is closed, and a -short time thereafter theloaded check valve 39 mediately operate, and the pressure in the lineconduit B will therefore build up, and this pressure will be transmittedthrough the lower end `of the bore 29 of the control valve 22 andconduit 66 to the lower end of the bore 28 of control valve 420. Thislubricant pressure, added to the force,

applied by the spring 54 which is compressed be- When the valve 48 movesf tween the piston 46 and the lower end of bore 29, will cause thepiston valve member 44 to move upwardly, causing the valve 48 to sealagainst its seat 34, and opening the vent valve 50 to relieve thepressure on Ithe lubricant in the line conduit A and to permit some ofit to be vented to the lubricant reservoir I0 through the vent conduit68.

As soon as the pressure in the line conduit A is relieved, the feedervalves commence operating to discharge measured charges of lubricant tothe others of the bearings 62 associated therewith. When all-of thefeeder valves 60 have thus been operated in the return direction by thelubricant under pressure supplied through the line conduitB, thepressure in the latter conduit will rise and as a result the pressurewill also build up in the conduit I5 to a value above that previouslyrequired for the operation -of the control valve 22 to a pressure such,for examplaas 1400 p. s. i., when the relief valve 12 will be forcedfrom its seat, permitting the lubricant to flow from the conduit I 6 tothe vent conduit 68. Such iiow of lubricant will continue during theremaining portion of the operating cycle of the motor driven pump I2 andwill, of course, stop when the time switch I4 operates to cut oli` thecurrent supply to the motor driven pump.

As the pump stops operation, the pressure in the conduit IB will dropdue to the venting of the lubricant therein past the valve 12, thisvalve remaining open dueto the fact that the effective area of thepiston 1S is very much greater than that of the seat for the valve 12.The pressure in the conduit I6 will therefore drop to a relatively lowvalue as, for example, p. s. i., and the valve member v44 of the controlvalve 22 will therefore be returned to its uppermost position by itsspring 55, thus completing a cycle of operation.

It will be noted that all `of the pistons for operating the variousvalves of the control system are provided with suitable sealing rings88, and i-t is thus not essential that the pistons and the cylindricalbores in which they operate be finished to a high degree of precision,and these parts may therefore be made by customary machining methodswithout the possibility of affecting the satisfactory operation of thecontrol apparatus.

In order to simplify and make more clear the intended meanings of some'of the claims, symbols indicating relative pressure have been employed.These symbols, and the exemplary values of the pressures which theyrepresent, are as follows:

u-The pressure at which valve 12 of Ithe relief mechanism 24 closes, e.g., 100 p. s. i.

v-The pressure at which check valves 38 and 39 open, e. g., 200 p. s. i.

x-The pressure at which the inlet valve 48 of the valve mechanism 20opens, e. g., 1000 p. s. i.

y--The pressure at which the valve 49 of the device 22 opens, e. g.,1200 p. s. i.

e-The pressure at which the valve 12 of the relief valve mechanism 24opens, e. g., 1400 p. s. 1.

It will be understood that the exemplary pressures are merelyillustrative, and that they should be considered as indicating merelyrelative, rather than the absolute, values, that is, pressure v isgreater than u, pressure :c greater than v, etc.

4 Furthermore, it will b'e understood that theA apparatus may be madeoperative without the Ause of the pressure relief valve 24, since thepump may be made to operate periodically and its discharge line ventedautomatically upon cessationl Yof operation. Similarly, the valves 38and 39 are not essential, although they may be used to increase thepositiveness and reliability of the operation of the hydraulic devices20 and 22.

While I have shown and described a preferred embodiment of my invention,it will be apparent that numerous variations and modifications thereofmay be made without departing from the underlying principles of theinvention. I therefore desire, bythe following claims, to include withinthe scope of the invention all such Variations and modifications bywhich substantially the results of my invention may be obtained throughthe use of substantially the same or equivalent means.

I claim: Y

1. A hydraulic apparatus which has parts, operable at pressures u, 1:,1v, y, and z, of progressively greater values, for controlling thedistribution of lubricant to rst and second conduits A and B from asource in which the pressure may at intervals build up to z; meansproviding a vent space in which the pressure is less than u; two springreturned valve devices respectively connected to the rst and secondconduits A and B, to the source, and to the vent space; the rst of saidvalve devices operating from a normal position to an operated positionto connect the source to first conduit A when the source pressureexceeds to close the connection to the vent space, and to maintain itsoperated position as long as Athe source pressure is more than v andless than exceeds y, and to maintain the second valve de- 4 vice inoperated position as long as the source pressure substantially exceedsu; means operated by substantial pressure in second conduit B to causethe first valve device to return to its normal position, and pressurerelief means connected to the source and spring biased to be opened whenthe source pressure exceeds e and elfective to reduce the sourcepressure until it reaches 2. An apparatus for alternately connecting twoconduits of a two conduit centralized lubricating system respectively toa space of low pressure and to a source of lubricant under high pressurecomprising, two hydraulically operated devices connected to the source,to the conduits respectively, and to the low pressure spa-ce; a springopposed valve in each of said devices, said valves operating atdifferent pressures at the source to connect the source to itsassociated conduit and to prevent ow from the conduit to said lowpressure space; hydraulic means rendered effective after operation ofthe valve operating at higher pressure to cause the other valve tooperate to disconnect its associated conduit from the source and toconnect it to the low pressure space, and a relief valve operable torelease the pressure of the lubricant from the source to a value lowerthan that required to operate the lower pressure valve Whenever thepressure substantially exceeds that required for the operation of thehigher pressure valve.

HARRY R. TEAR.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 1,805,303 Barks May 12, 1931 1,990,986 Fox Feb. 12, 19352,007,156 Burrell July 9, 1935 2,019,299 Fox Oct. 29, 1935 2,052,664Rotter Sept. 1, 1936

